Processes for preparing bis-naphthalimides containing amino-acid derived linkers

ABSTRACT

This invention relates to bis-naphthalimides, including 2,2&#39;-[1,2-ethanediylbis[imino(1-methyl-2,1-ethanediyl)]]-bis[5-nitro-1H-benz[de]isoquinoline-1,3(2H)-dione] and 2,2&#39;-[1,2-ethanediylbis[imino(2-methyl-2,1-ethanediyl)]]-bis[5-nitro-1H-benz[de]isoquinoline-1,3(2H)-dione], processes for their preparation, pharmaceutical compositions containing them, and methods of using them to treat cancer in mammals.

CROSS REFERENCE TO EARLIER FIELD APPLICATION

This application is a continuation-in-part of U.S. patent application Ser. No. 08/025,633, filed Feb. 16, 1993, now U.S. Pat. No. 5,329,048, which is a divisional of U.S. patent application Ser. No. 07/805,044, filed Dec. 11, 1991, now U.S. Pat. No. 5,206,249, which is a continuation-in-part of U.S. patent application Ser. No. 07/676,061, filed Mar. 27, 1991, now abandoned. The disclosure of these earlier filed applications is hereby incorporated herein by reference.

FIELD OF THE INVENTION

This invention relates to bis-naphthalimides, including 2,2'-[1,2-ethanediylbis[imino(1-methyl-2,1-ethanediyl)]]-bis[5-nitro-1H-benz[de]isoquinoline-1,3(2H) -dione] and 2,2'-[1,2-ethanediylbis[imino(2-methyl-2,1-ethanediyl)]]-bis[5-nitro-1H-benz[de]isoquinoline-1,3(2H) -dione], processes for their preparation, pharmaceutical compositions containing them, and methods of using them to treat cancer, particularly solid tumor carcinomas, in mammals.

BACKGROUND OF THE INVENTION

Harnisch et al., U.S. Pat. No. 4,841,052 issued Jun. 20, 1989 describe naphthalic acid imides useful as charge-regulating substances in electrophotographic toners.

Brana et al., U.S. Pat. No. 4,874,863 issued Oct. 17, 1989 discloses anticancer compounds of the formula: ##STR1## wherein X¹, X², X³ and X⁴ are identical or different and are each H, NO₂, NH₂, C₁ -C₆ -alkylamino, di-C₁ -C₆ -alkylamino, OH, C₁ -C₆ -alkoxy, halogen, trihalomethyl, C₁ -C₆ alkyl, formyl, C₁ -C₆ -alkylcarbonyl, ureyl, C₁ -C₆ -alkylureyl and R is a straight chain or branched C₄ -C₁₀ -alkylene which is interrupted at one or two points in the chain by a secondary or tertiary amino group, where 2 nitrogen atoms may additionally be bonded to one another by an alkylene group, or a salt with a physiologically tolerated acid.

DETAILED DESCRIPTION OF THE INVENTION

There is provided by this invention bis-naphthalimide compounds having the formula (i): ##STR2##

or enantiomeric or diastereomeric forms thereof, or mixtures of enantiomeric or diastereomeric forms thereof, or pharmaceutically acceptable salts thereof, wherein:

R¹, R², R³, R⁴, R⁵, R⁶, and R⁷, independently, are H or CH₃ ;

X and X' are H or NO₂ ; and

Y and Y' are H or NO₂, provided that at least one of X, X', Y, and Y' is NO₂.

Preferred compounds of the present invention include those compounds of formula (i) wherein:

R¹ and R⁷ are CH₃ ;

R², R³, R⁴, R⁵, and R⁶ are H;

X and X' are NO₂, wherein the substituent is at the 3-position of the naphthalimide (i.e., the 5-position of the 1H-benz[de]isoquinoline-1,3(2H)-dione; and

Y and Y' are H.

Preferred compounds of the present invention also include those compounds of formula (i) wherein:

R² and R⁶ are CH₃ ;

R¹, R³, R⁴, R⁵, and R⁷ are H;

X and X' are NO₂, wherein the substituent is at the 3-position of the naphthalimide (i.e., the 5-position of the 1H-benz[de]isoquinoline-1,3(2H)-dione); and

Y and Y' are H.

Specifically preferred compounds of the present invention are the following:

(S,S)-2,2'-[1,2-ethanediylbis[imino(1-methyl-2,1-ethanediyl)]]-bis[5-nitro-1H-benz[de]isoquinoline-1,3(2H)-dione];

(Racemic+Meso)-2,2'-[1,2-ethanediylbis[imino(1-methyl-2,1-ethanediyl)]]-bis[5-nitro-1H-benz[de]isoquinoline-1,3(2H)-dione];

(R,R)-2,2'-[1,2-ethanediylbis[imino(1-methyl-2,1-ethanediyl)]]-bis[5-nitro-1H-benz[de]isoquinoline-1,3(2H)-dione];

(Meso)-2,2'-[1,2-ethanediylbis[imino(1-methyl-2,1-ethanediyl)]]-bis[5-nitro-1H-benz[de]isoquinoline-1,3(2H)-dione];

(S,S)-2,2'-[1,2-ethanediylbis[imino(2-methyl-2,1-ethanediyl)]]-bis[5-nitro-1H-benz[de]isoquinoline-1,3(2H)-dione];

(Racemic+Meso)-2,2'-[1,2-ethanediylbis[imino(2-methyl-2,1-ethanediyl)]]-bis[5-nitro-1H-benz[de]isoquinoline-1,3(2H)-dione];

(R,R)-2,2'-[1,2-ethanediylbis[imino(2-methyl-2,1-ethanediyl)]]-bis[5-nitro-1H-benz[de]isoquinoline-1,3(2H)-dione]; or

(Meso)-2,2'-[1,2-ethanediylbis[imino(2-methyl-2,1-ethanediyl)]]-bis[5-nitro-1H-benz[de]isoquinoline-1,3(2H)-dione];

and pharmaceutically acceptable salts thereof.

Also provided by this invention are processes for the preparation of the compounds of formula (i), pharmaceutical compositions containing the compounds of formula (i), and methods of using these compounds for the treatment of cancer, particularly solid tumor carcinomas, in a mammal.

The compounds provided by this invention are also useful as standard or reference compounds for use in tests or assays for determining the ability of an agent to inhibit human tumors xenografted in mice, for example in a pharmaceutical research program. Thus, the compounds of the present invention may be used as a control or reference compound in such assays and as a quality control standard. The compounds of the present invention may be provided in a commercial kit or container for use as such standard or reference compound.

As used herein, the term "amine protecting group" means any group known in the art of organic synthesis for the protection of amine groups. Preferred amine protecting groups include those which may be removed without the addition of an acid, and which thereby allow for the direct isolation of the free base form of the compound of formula (XXXXVII) or (XXXXVIII), rather than an acid addition salt form. Such amine protecting groups include those listed in Greene and Wuts, "Protective Groups in Organic Synthesis", 2nd Edition, John Wiley & Sons, New York (1991) and "The Peptides: Analysis, Sythesis, Biology, Vol. 3, Academic Press, New York (1981), the disclosure of which is hereby incorporated by reference. Preferred amine protecting groups and preferred conditions for their removal include, but are not limited to, those listed below.

                  TABLE 1                                                          ______________________________________                                                           Preferred Nonacidic                                          Protecting Group, Abbreviation                                                                   Removal Conditions                                           ______________________________________                                         2,7-di-t-butyl-[9-(10,10-dioxo-                                                                  hydrogenation with                                           10,10,10,10-tetrahydrothio-                                                                      Pd/carbon (Pd/C),                                            xanthyl)]methyl carbamate,                                                                       HCO.sub.2 NH.sub.4 in methanol                               DBD-Tmoc                                                                       2-trimethylsilylethyl                                                                            ZnCl.sub.2 in CH.sub.3 NO.sub.2                              carbamate, Teoc                                                                2-phenylethyl carbamate, hZ                                                                      hydrogenation with                                                             Pd (OAc).sub.2, HCO.sub.2 NH.sub.4                           1,1-dimethyl-2,2-dibromoethyl                                                                    solvolysis with ethanol                                      carbamate, DB-t-Boc                                                            1-methyl-1-(4-biphenylyl)ethyl                                                                   tetrazole in                                                 carbamate, Bpoc   trifluoroethanol                                             benzyl carbamate, Cbz                                                                            hydrogenation with Pd/C                                                        in methanol                                                  p-nitrobenzyl carbamate                                                                          hydrogenation with Pd/C                                                        in methanol                                                  2-(p-toluenesulfonyl)ethyl                                                                       1 M NaOH in alcohol                                          carbamate                                                                      m-chloro-p-acyloxybenzyl                                                                         hydrogenation with Pd/C                                      carbamate                                                                      5-benzyisoxazolylmethyl                                                                          hydrogenation with Pd/C                                      carbamate, Bic                                                                 p-(dihydroxyboryl)benzyl                                                                         hydrogenation with Pd/C                                      carbamate, Dobz                                                                m-nitrophenyl carbamate                                                                          photolysis                                                   o-nitrobenzyl carbamate                                                                          photolysis                                                   3,5-dimethoxybenzyl carbamate                                                                    photolysis                                                   3,4-dimethoxy-6-nitrobenzyl                                                                      photolysis                                                   carbamate                                                                      N'-p-toluenesulfonylamino-                                                                       alcoholysis                                                  carbonyl                                                                       t-amyl carbamate  hydrogenation with Pd/C                                      p-decyloxybenzyl carbamate                                                                       hydrogenation with Pd/C                                      diisopropylmethyl carbamate                                                                      hydrogenation with Pd/C                                      2,2-dimethoxycarbonylvinyl                                                                       hydrogenation with Pd/C                                      carbamate                                                                      di(2-pyridyl)methyl carbamate                                                                    hydrogenation with Pd/C                                      2-furanylmethyl carbamate                                                                        hydrogenation with Pd/C                                      phthalimide       CH.sub.3 NH.sub.2 in ethanol                                 dithiasuccinimide, Dts                                                                           mercaptoethanol and Et.sub.3 N                               2,5-dimethylpyrrole                                                                              ozonolysis                                                   benzyl            Na and NH.sub.3                                              5-dibenzylsuberyl hydrogenation with Pd/C                                      triphenylmethyl, Tr                                                                              hydrogenation with Pd                                                          black                                                        benzylidene       hydrogenation with Pd/C                                      diphenylmethylene hydrogenation with Pd/C                                      9-(2-sulfo)fluorenylmethyl                                                                       0.1 N NH.sub.4 OH; 1% Na.sub.2 CO.sub.3                      carbamate                                                                      9-(2,7-dibromo)fluorenylmethyl                                                                   piperidine                                                   carbamate                                                                      9-fluorenylmethyl carbamate                                                                      piperidine, morpholine                                       ______________________________________                                    

As used herein, the term "carboxyl activating agent" means any such agent or combination of agents which will effect the formation of an activated carboxyl group and/or any such agent as commonly used in the art of protein or synthetic organic chemistry to effect the formation of peptide or amide bonds. Such agents include, by way of example and without limitation, those listed in Gross and Meienhofer, "The Peptides: Analysis, Synthesis, Biology, Vol. 1", Academic Press, New York (1979), the disclosure of which is hereby incorporated by reference. Such agents include, but are not limited to, anhydrides, azides, cyanides, carbodiimides, aryl esters, carbonyldiimidazole, phosgene, oxalylchloride, thionylchloride, thionylbromide, and alcohols. Preferred carboxyl activating agents include, but are not limited to: N-ethyloxycarbonyl-2-ethyloxy-1,2-dihydroquinoline (EEDQ), N-isobutyloxycarbonyl-2-isobutyloxycarbonyl-1,2-dihydroquinoine (IIDQ), or an alkyl chlorocarbonate, such as isobutyl chlorocarbonate, which yield mixed anhydride activated carboxyl groups; diphenylphosphorazidate which yields azide activated carboxyl groups; and carbonyldiimidazole, ethoxyacetylene, or dicyclohexylcarbodiimide (the latter two preferrably reacted in the presence of 1-hydroxybenzotriazole or N-hydroxysuccinimide) which yield active ester activated carboxyl groups.

As used herein, the term "amide reducing agent" is meant to be any reagent or combination of reagents and/or conditions which will effect the reduction of an amide compound of formula (XXXXVIII) to an amine compound of formula (IV). Preferred amide reducing agents are those which allow for direct isolation of the free base form of the amine compound of formula (IV) from the reaction medium, and those amide reducing agents which do not result in the formation of distillable complexes of the amine and the amide reducing agent (i.e., do not result in the formation of complexes which distill with the compound of formula (IV)). Such amide reducing agents include those listed in March, "Advanced Organic Chemistry: Reactions, Mechanisms and Structure" 3rd Edition, John Wiley & Sons, New York (1985), the disclosure of which is hereby incorporated by reference. Preferred amide reducing agents include, but are not limited to, lithium aluminum hydride (LAH), AlH₃, diisobutyl aluminum hydride (DIBAL-H), NaAlEt₂ H₂, sodium bis(2-methoxyethoxy)aluminum hydride (RED-AL®), or catalytic hydrogenation with Raney nickel of a corresponding thioamide.

The present invention includes a process for preparing the free base form of a compound of formula (IV): ##STR3## comprising the steps of:

(a) reacting in solution a compound of the formula: ##STR4## wherein R¹⁰ is an amine protecting group that can be removed without the addition of acid,

with a suitable carboxyl activating agent, said carboxyl activating agent facilitating the formation of an amide bond,

followed by reaction with ethylenediamine to yield a compound of formula (XXXXVII): ##STR5##

(b) contacting the compound of formula (XXXXVII) with a suitable reagent or combination of reagents to effect the removal, without the addition of acid, of the R¹⁰ amine protecting groups from the compound of formula (XXXXVII) to yield in solution the free base form of the compound of the formula (XXXXVIII): ##STR6##

(c) isolating the compound of formula (XXXXVIII) by removal of unwanted solids from the reaction medium and contacting the reaction solution with a suitable solvent to effect precipitation of the compound of formula (XXXXVIII);

(d) reacting the resultant compound of formula (XXXXVIII) in solution with a suitable amide reducing agent, said amide reducing agent not resulting in the formation of distillable complexes of the amine reducing agent and the compound of formula (IV), to yield the free base form of the compound of formula (IV).

Preferred R¹⁰ amine protecting groups in the above process of the present invention include, but are not limited to the following:

2,7-di-t-butyl-[9-(10,10-dioxo-10,10,10,10-tetrahydrothio-xanthyl)]methyl carbamate;

2-trimethylsilylethyl carbamate;

2-phenylethyl carbamate;

1,1-dimethyl-2,2-dibromoethyl carbamate;

1-methyl-1-(4-biphenylyl)ethyl carbamate;

benzyl carbamate;

p-nitrobenzyl carbamate;

2-(p-toluenesulfonyl)ethyl carbamate;

m-chloro-p-acyloxybenzyl carbamate;

5-benzyisoxazolylmethyl carbamate;

p-(dihydroxyboryl)benzyl carbamate;

m-nitrophenyl carbamate;

o-nitrobenzyl carbamate;

3,5-dimethoxybenzyl carbamate;

3,4-dimethoxy-6-nitrobenzyl carbamate;

N'-p-toluenesulfonylaminocarbonyl;

t-amyl carbamate;

p-decyloxybenzyl carbamate;

diisopropylmethyl carbamate;

2,2-dimethoxycarbonylvinyl carbamate;

di(2-pyridyl)methyl carbamate;

2-furanylmethyl carbamate;

phthalimide;

dithiasuccinimide;

2,5-dimethylpyrrole;

benzyl;

5-dibenzylsuberyl;

triphenylmethyl;

benzylidene;

diphenylmethylene; or

methanesulfonamide.

Further preferred R¹⁰ amine protecting groups in the above process are: 2-phenylethyl carbamate; benzyl carbamate; p-nitrobenzyl carbamate; 2-(p-toluenesulfonyl)ethyl carbamate; 5-benzyisoxazolylmethyl carbamate; m-nitrophenyl carbamate; o-nitrobenzyl carbamate; 3,5-dimethoxybenzyl carbamate; 3,4-dimethoxy-6-nitrobenzyl carbamate; p-decyloxybenzyl carbamate; di(2-pyridyl)methyl carbamate; 2-furanylmethyl carbamate; phthalimide; benzyl; or diphenylmethylene. A preferred amine protecting group R¹⁰ is benzyl carbamate.

Preferred reagents or conditions to effect the removal of R¹⁰ include, but are not limited to the following, or combinations thereof: hydrogenation with HCO₂ NH₄ in methanol; ZnCl₂ in CH₃ NO₂ ; hydrogenation with Pd(OAc)₂, HCO₂ NH₄ ; solvolysis with ethanol; tetrazole in trifluoroethanol; hydrogenation with Pd/C; 1M NaOH in alcohol; photolysis; alcoholysis; CH₃ NH₂ in ethanol; mercaptoethanol and Et₃ N; ozonolysis; Na and NH₃ ; or hydrogenation with Pd black; where the selection of R¹⁰ will dictate the judicious selection of the most suitable reagent or combination of reagents above.

Preferred above-described processes of the present invention are those wherein in step (c) the suitable solvent to effect precipitation of the compound of formula (XXXXVIII) is t-butylmethyl ether (t-BME). Also preferred are those methods wherein step (c) comprises contacting the reaction solution or solvent exchanging of the reaction solution with t-BME to precipitate the compound of formula (XXXXVIII) followed by separation of solids from liquid (for example, by filtration) to isolate the compound of formula (XXXXVIII).

Preferred amide reducing agents in the above process of the present invention include, but are not limited to, the following: lithium aluminum hydride, AlH₃, diisobutyl aluminum hydride, NaAlEt₂ H₂, sodium bis(2-methoxyethoxy)aluminum hydride, or catalytic hydrogenation with Raney nickel of a corresponding thioamide. A preferred amide reducing agent is lithium aluminum hydride.

Preferred carboxyl activating agents in the above process of the present invention include, but are not limited to: anhydrides, azides, cyanides, carbodiimides, aryl esters, carbonyldiimidazole, phosgene, oxalylchloride, thionylchloride, thionylbromide, and alcohols. A preferred carboxyl activating agent is 1,1'-carbonyldiimidazole.

The reactions of the synthetic methods claimed herein are carried out in suitable solvents which may be readily selected by one of skill in the art of organic synthesis, said suitable solvents generally being any solvent which is substantially nonreactive (except where the solvent also functions as the suitable base, as discussed below) with the starting materials (reactants), the intermediates, or products at the temperatures at which the reactions are carried out, i.e., temperatures ranging from the solvent's freezing temperature to the solvent's boiling temperature. Depending on the particular reaction step, suitable solvents for a particular reaction step may be selected and may include aprotic solvents, including but not limited to polar aprotic organic solvents. Depending on the particular reaction step, suitable solvents for a particular reaction step may be selected and may include, but are not limited to, toluene, pyridine, dimethylsulfoxide (DMSO), N,N-dimethylformamide (DMF), N,N-dimethylacetamide (DMAC), diethyl ether, benzene, or tetrahydrofuran.

Synthesis

The present invention describes a series of bis-naphthalimides useful for treating cancer containing linkers derived from reduced peptides. Compounds of this invention are more soluble in aqueous media than prior art compounds not containing these reduced peptide linkers.

Compounds of this invention can be synthesized by reacting two equivalents of an anhydride of formula (ii) with one equivalent of a polyamine of formula (iii) in an inert solvent such as ethanol or dimethylformamide or tetrahydrofuran, for example, at a temperature ranging from ambient to the solvent's boiling temperature (Scheme A). The resulting suspension can then be filtered to give the free base of (i) or it can be acidified with the appropriate mineral or organic acid to produce a pharmaceutically acceptable salt, which can be obtained by filtration. Salts of the free base can also be prepared by acidifying a suspension of the free base in ethyl alcohol or dichloromethane with the appropriate mineral or organic acid and collecting the formed solid by filtration. In some cases, the free base of (i) requires purification by column chromatography before its salt can be prepared as described above. ##STR7##

The parent anhydride (ii) is commercially available or can be prepared according to the procedures described by Hodgson et al., J. Chem. Soc., p90 (1945). Reduced peptides of formula (iii) can be prepared according to the methods described below (Schemes I-IV).

The synthesis of compounds of formula Va may be carried out by two different routes (see Scheme I and Scheme VII below). In Scheme I, the reaction of t-BOC-(S)-alanine (compound a) with 1,1'-carbonyldiimidazole, followed by reaction with ethylenediamine under standard conditions afforded compound Ia. Acid hydrolysis of the t-BOC (N-tert-butoxycarbonyl) protecting group in Ia was performed under standard conditions to afford IIa. The same procedure is utilized to produce compounds IIb or IIc by starting the sequence with the corresponding (R)-alanine (compound b) or racemic alanine (compound c).

Reduction of IIa (dihydrochloride salt) with diborane in tetrahydrofuran at refluxing temperature afforded IIIa. IIIa was then neutralized with sodium ethoxide and the pure free base IVa was obtained by Kugelrohr distillation. IVa was reacted with the appropriate naphthalic anhydride in ethanol or tetrahydrofuran at reflux temperature to obtain Va. Compounds Vb and Vc are prepared similarly by using the corresponding IVb or IVc, respectively. ##STR8##

Bis-naphthalimides of the formula (XIX) where R¹ ═R³ ═R⁴ ═R⁵ ═R⁷ ═H, R² ═R⁶ ═CH₃ and X and Y are NO₂ or H can be made by Scheme III. Reaction of (S)-alanine methyl ester with oxalyl chloride in benzene at reflux temperature gave amide XVa. Amide XVa was converted to amide XVIa with ammonia in methanol under standard conditions. Amide XVIa was reduced with diborane in tetrahydrofuran to yield amine XVIIa as the tetrahydrochloride salt which was subsequently neutralized with sodium ethoxide to yield the free amine XVIIIa. Amine XVIIIa was condensed with the appropriate naphthalic anhydride to produce compound XIXa. Compounds XIXb and XIXc could be prepared similarly by using the corresponding compounds XVIIIb and XVIIIc, respectively. In addition, compounds XXa, XXVIIIb and XXIXb could be prepared by condensation of amine XVIIIb with appropriate naphthalic anhydrides. ##STR9##

In Scheme III the position of X and Y is indicated using the numbering for the position in the corresponding naphthalic anhydride, and not the numbering for the 1H-benz[de]isoquinoline-1,3(2H)-dione.

For compounds of the formula (XXVII), the synthesis is shown in Scheme IV. Reaction of t-BOC-(S)-alanine with isobutylchloroformate in the presence of N-methylmorpholine, followed by reaction with aminoacetonitrile (generated by neutralization of its HCl salt with N-methylmorpholine), gave XXI. This was hydrogenated with palladium hydroxide in acetic acid to yield XXII. Reaction of t-BOC-(R)-alanine with 1,1'-carbonyldiimidazole, followed by addition of XXII under standard conditions, afforded XXIII. Acid hydrolysis of the t-BOC protecting group of XXIII was carried out under standard conditions to furnish XXIV. Subsequent reduction with diborane in refluxing tetrahydrofuran yielded XXV, which was neutralized with sodium ethoxide to give XXVI. Amine XXVI was condensed with the appropriate naphthalic anhydride to produce XXVII. ##STR10##

For compounds of the formula (XXXX), the synthesis is shown in Scheme V (below). (t-BOC)-Alaninyl alanine was reacted with isobutyl chloroformate in methylene chloride at -10° to -15° C. in the presence of N-methylmorpholine, followed by addition of (S)-alanine methylester hydrochloride to give XXXV. The ester XXXV was converted to its amide XXXVI by bubbling ammonia in methanol. The t-BOC protecting group was removed by acid hydrolysis to furnish XXXVII. Subsequent diborane reduction of tripeptide amide XXXVII in refluxing tetrahydrofuran yielded the polyamine tetrahydrochloride XXXVIII, which was neutralized with sodium ethoxide to yield XXXIX. The amine XXXIX was condensed with the appropriate naphthalic anhydride to produce XXXX. ##STR11##

Asymmetric bis-naphthalimides of the formula (XXXXVI) can be synthesized as shown in Scheme VI (below). Reaction of XXII with 1,1'-carbonyldiimidazole, followed by addition of (R)-benzyloxycarbonyl alanine, furnished XXXXI. Subsequent reaction with phosphorus pentasulfide in tetrahydrofuran gave the corresponding thioamide XXXXII. Treatment of XXXXII with Raney Nickel yielded amine XXXXIII. Amine XXXXIII was condensed with 3-nitro-1,8-naphthalic anhydride to yield naphthalimide XXXXIV. The (t-BOC) protecting group was hydrolyzed under standard conditions to give XXXXV, which in turn can be condensed with another naphthalic anhydride to produce non-symmetric bis-naphthalimides of the formula XXXXVI. ##STR12##

An alternative method for synthesis of compounds of formula V is outlined in Scheme VII below and described in detail in Example 3a. In Scheme VII, the Cbz (N-benzyloxycarbonyl) group is a representative amine protecting group which can be removed without the addition of acid, as defined above.

The reaction of Cbz-(S)-alanine (compound a) with 1,1'-carbonyldiimidazole (which is a representative suitable carboxyl activating agent as defined above), followed by reaction with ethylenediamine afforded compound XXXXVIIa. Hydrogenolysis to remove the Cbz protecting group in XXXXVIIa provided compound XXXXVIIIa in the free base form in solution. The combined purification and isolation of XXXXVIIIa may be carried out by exchanging the methanol reaction solvent (a representative reaction solvent) with t-butylmethyl ether (t-BME) (a representative suitable solvent to effect the precipitation of compound XXXXVIII) to provide the XXXXVIIIa product in pure solid form. No additional purification was needed using these preferred conditions. The same procedure may be utilized to prepare compounds XXXXVIIIb or XXXXVIIIc by starting the sequence with the corresponding (R)-alanine (compound b) or racemic alanine (compound c).

Reduction of the free base form of XXXXVIIIa with lithium aluminum hydride (LAH) (a representative suitable amide reducing agent as defined above) in tetrahydrofuran (or other suitable solvent) at refluxing temperature afforded IVa which was obtained in pure form by simple vacuum distillation following a NaOH/H₂ O quench and THF extraction of the aluminate salts. Compound IVa was reacted with the appropriate naphthalic anhydride in dioxolane at 60° C.-80° C. to obtain Va. Compounds Vb and Vc may be prepared similarly by using the starting compound IVb or IVc, respectively. ##STR13##

The invention can be further understood by referring to the following Examples and Tables below.

EXAMPLE 1 (S,S)-2,2'-[1,2-ethanediylbis[imino(1-methyl-2,1-ethanediyl)]]-bis[5-nitro-1H-benz[de]isoquinoline-1,3(2H)-dione]methanesulfonate (1:2) (Va)

Part A: (IIIa) (S,S)-N¹,N^(1') -1,2-ethanediylbis[1,2-propanediamine]tetrahydrochloride.

To a THF (80 ml) suspension of IIa (2.75 g, 10 mmol), there was added 200 ml of 1M BH₃.THF complex slowly. The mixture was stirred at room temperature for 11/2 hours and then heated overnight to become a clear solution. After cooling to room temperature, the solution was carefully quenched with 100 ml of methanol, and then refluxed overnight. The solvent was evaporated, and to the remaining liquid was added 20 ml of methanol and 5 ml of conc. HCl. The resulting white solid was collected on a filter under nitrogen to give 1.92 g (60%) of IIIa; mp 210°-215° C. ¹ H-NMR (D₂ O) δ 3.60 (m, 2H, 2 CH), 3.40 (s, 4H, 2 CH₂), 3.27 (m, 4H, 2 CH₂) and 1.30 (d, 6H, J=6.9 Hz, 2 CH₃). MS (DCI) m/e 175 (M+1, free base). [α]_(D) -2.31° (c=0.606, H₂ O).

Part B: (IVa) (S,S)-N¹,N^(1') -1,2-ethanediylbis[1,2-propanediamine].

Sodium (1.03 g, 45 mmol) was added to 50 ml of anhydrous ethanol; and the mixture stirred for 1.5 hours until all the sodium was dissolved. To this, there was added 3.2 g (10 mmol) of IIIa. After stirring for 2 hours, the sodium chloride precipitate was removed by filtration; and the solvent in the filtrate evaporated. Kugelrohr distillation (120°-140° C. at 1.4 mm) gave 1.29 g (74%) of IVa as a clear liquid. ¹ H-NMR (CDCl₃) δ 2.96 (m, 2H, 2 CH), 2.71 (m, 4H, 2 CH₂), 2.60 (m, 2H, CH₂), 2.40 (m, 2H, CH₂), 1.46 (broad, 6H, 2 NH₂ and 2 NH) and 1.06 (d, 6H, J=6.2 Hz, 2 CH₃). MS (DCI) m/e 175 (M+1).

Part C: (Va) (S,S)-2,2'-[1,2-ethanediylbis[imino(1-methyl-2,1-ethanediyl)]]-bis[5-nitro-1H-benz[de]isoquinoline-1,3(2H)-dione]methanesulfonate (1:2).

A mixture of 3-nitro-1,8-naphthalic anhydride (2.43 g, 10 mmol) and IVa (0.87 g, 5 mmol) was stirred at room temperature for 4 hours, refluxed for 2 hours and then cooled to room temperature overnight. The solvent in the mixture was evaporated and the residue purified by column chromatography to give 0.87 g (27.9%) of a brown solid. The free base (0.84 g, 1.3 mmol) in 70 ml of methylene chloride was added 0.26 g of methanesulfonic acid. After stirring at room temperature overnight, the solvent in the mixture was evaporated, and 45 ml of methanol was added to the residue. After refluxing for 2 hours. The yellow solid was collected on a filter, dried in vacuo at 78° C. for 2 hours to give 0.86 g (81%) of Va mp 212°-213° C. (dec). ¹ H-NMR (DMSO-d₆) δ 9.53 (d, 2H, J=2.2 Hz, aromatic protons), 8.96(d, 2H, J=2.2 Hz, aromatic protons), 8.83 (d, 2H, J=7.7 Hz, aromatic protons), 8.69 (d, 2H, J=7.3 Hz, aromatic protons), 8.7- 8.8 (broad, 4H, 2 NH₂ ⁺), 8.09 (t, 2H, J=7.9 Hz, aromatic protons), 5.46 (m, 2H, 2 CH), 3.86 (m, 2H), 3.2-3.5 (m, 6H), 2.20 (s, 6H, 2 CH₃) and 1.57 (d, 6H, J=6.9 Hz, 2 CH₃). MS (DCI) m/e 625 (M+1). Anal. Calcd for C₃₂ H₂₈ N₆ O₈ . 2 CH₃ SO₃ H (MW 816.81): C, 50.00; H, 4.44; N, 10.29; S, 7.85. Found: C, 49.88; H, 4.39; N, 10.14; S, 7.86.

Similarly, Examples 2 and 3 may be prepared and characterized according to Example 1.

EXAMPLE 2 (Racemate+meso)-2,2'-[1,2-ethanediylbis[imino(1-methyl-2,1-ethanediyl)]]-bis[5-nitro-1H-benz[de]isoquinoline-1,3(2H) -dione]methanesulfonate (1:2) (Vc)

Light yellow solid (18% yield); mp 220°-221° C. (dec). ¹ H-NMR of Vc is almost identical with that of Va except that Vc shows d of d at δ 1.59 ppm due to the presence of dl pair and meso. MS(DCI) m/e 625 (M+1). Anal. Calcd for C₃₂ H₂₈ N₆ O₈ . 2 CH₃ SO₃ H . H₂ O (MW 834.83): C, 48.92; H, 4.59; N, 10.07; S, 7.68. Found: C, 49.10, 49.01; H, 4.45, 4.40; N, 10.02, 9.96; S, 7.39, 7.45.

EXAMPLE 3 (R,R)-2,2'-[1,2-ethanediylbis[imino(1-methyl-2,1-ethanediyl)]]-bis[5-nitro-1H-benz[de]isoquinoline-1,3(2H)-dione]methanesulfonate (1:2) (Vb)

Light yellow solid (25% yield); mp 210°-211° C. (dec). The ¹ H-NMR of Vb is identical with that of Va. MS (DCI) m/e 625 (M+1). Anal. Calcd for C₃₂ H₂₈ N₆ O₈ . 2 CH₃ SO₃ H (MW 816.81): C, 50.00; H, 4.44; N, 10.29; S, 7.85. Found: C, 49.98; H, 4.41; N, 10.14; S, 7.81.

EXAMPLE 3a (R,R)-2,2'-[1,2-ethanediylbis[imino(1-methyl-2,1-ethanediyl)]]-bis[5-nitro-1H-benz[de]isoquinoline-1,3(2H)-dione]methanesulfonate (1:2) (Vb)

Part A: (XXXXVIIb) (R,R)-bis(phenylmethyl) 1,2-ethanediylbis[imino(1-methyl-2-oxo-2,1-ethanediyl)]bis[carbamate]

Cbz-D-alanine (5.5 moles) was stirred in a tetrahydrofuran solution (18.5 L) until dissolution was complete. The solution was chilled to -10° to 0° C. and kept at that temperature throughout the following operations in order to minimize racemization of the chiral center. Carbonyldiimidazole (5.55 moles) was added to the Cbz-D-alanine solution. The mixture was kept cooled (-10° to 0° C.) and stirred for 8.0 hour allowing for formation of the Cbz-D-alanine-imidazole intermediate. Ethylenediamine (2.75 moles) was added to the reaction slurry over 60 minutes while keeping the temperature below 0° C. The mixture was kept cooled (-10° to 0° C.) and stirred for 16.0 hours allowing for the formation of XXXXVIIb. Reaction progress was monitored by HPLC. The reaction mass was warmed to room temperature and water (65 moles) was added to quench the reaction. Begin solvent exchange (water for tetrahydrofuran) by heating the reaction to 65°-70° C. to effect distillation of tetrahydrofuran. During distillation, hydrochloric acid (11.1 moles of 37% wt) and sufficient water (18.5 L) to replace the distilled volume of tetrahydrofuran were added to the reactor. Upon completion of the solvent exchange, the reactor was cooled to 0° to 10° C. XXXXVIIb was isolated by filtration. The wet cake was purified by washing with cold water (3×3.0 L). XXXXVIIb was vacuum oven dried under nitrogen at 90° C. to a constant weight. Yield was 90% of theoretical of dry white to off white solid. Mp Range: 188.5°-189.5° C.; HPLC: >98% area; ¹ HNMR (TMS, CDCl₃): δ 1.20, 3.30, 4.15, 5.05, 6.25, 7.30, 7.60; (TMS, DMSO-d6): δ 1.20, 3.10, 3.94, 5.02, 7.35, 7.45, 7.90.

Part B: (XXXXVIIIb) (R,R)-N,N'-1,2-ethanediylbis[2-aminopropanamide]

XXXXVIIb (0.82 moles) was placed in anhydrous methanol (2.75 L) in the autoclave. Palladium on carbon (5% by wt, 7.1 g in 100 of methanol) catalyst was added to the reactor under inert atmosphere. The solution was heated at 50° C. and hydrogen was passed through the well stirred reaction slurry. Extent of hydrogenolysis was monitored by HPLC. After completion (18 hours) the temperature was lowered to 20°-30° C. The palladium on carbon was removed by filtration. The methanol was concentrated to approximately 200 mL and tert-butylmethyl ether (0.9 L) was added to precipitate the product. The slurry was cooled to 0°-10° C. for 1 hour. XXXXVIIIb was isolated by filtration and purified by washing with tert-butylmethyl ether (2×200 mL). XXXXVIIIb was dried in a vacuum oven with nitrogen purge at 40°-50° C. to a constant weight. Dried XXXXVIIIb was a fine white powder. Yield was 85% of theoretical. Mp Range: 137.0°-137.5° C.; ¹ HNMR (TMS, CD₃ OD): δ 1.25, 3.30, 3.35.

Part C: (IVb) (R,R)-N1,N1'-1,2-ethanediyl-bis[1,2-propanediamine]

LAH in tetrahydrofuran (12.0 moles of 1.0 Molar solution) was placed in the reactor. XXXXVIIIb (3.0 moles) was added to the LAH portionwise. The reactor was heated to 65°-67° C. to effect a reflux and maintained at that temperature for 20 hrs. Following completion of the reaction, the reactor was cooled to 20°-30° C. and quenched with a water (25 moles)/tetrahydrofuran (2.28 L) mixture over three hours while stirring vigorously. A mixture of sodium hydroxide (2.6 moles of 50% NaOH solution) and water (18 moles) was added over 30 min. Finally, water alone (76 moles) was added over 10 min. The mixture was heated to 60°-65° C. for 1 hr. The slurry was hot filtered to separate IVb from the lithium aluminate sodium salts. The wet filtercake was extracted with hot tetrahydrofuran (3×3.0 L, 60°-65° C.) to recover IVb adsorbed to the solids. Following removal of the solvent by distillation or evaporation, the IVb oil was vacuum distilled (Bp 81°-83° C. at 0.1-0.15 mm Hg) under an inert atmosphere. The yield was 86% of theoretical. GLC purity: >95% area; ¹ HMNR: (TMS, THF-d8) δ 0.95, 2.38, 2.63, 2.84; Optical Rotation: [α]_(D) =-40.0°-41.0°.

Part D: (Vb) (R,R)-2,2'-[1,2-ethanediylbis[imino(1-methyl-2,1-ethanediyl)]]bis[5-nitro-1H-benz[de]isoquinoline-1,3(2H)-dione]dimethanesulfonate (1:2);

All glassware in this step is ambered due to the light sensitivity of Va. 3-Nitro-1,8-naphthalic anhydride (3-NNA, 3.35 moles) was placed in a reactor containing dioxolane (14.8 L). IVb (1.72 moles) in dioxolane (150 mL) was added to the reactor over 2 hours. At the end of addition, the pot temperature was raised to 70°-75° C. The reaction was monitored by HPLC and TLC. Following completion (11 hrs), the temperature was lowered to 20°-30° C. and the reaction mass filtered. A solvent exchange from dioxolane to toluene (14.8 L) was performed in a rotoevaporator. The toluene-product slurry was loaded onto a silica gel column (use 2.2 Kg of dry silica gel) and eluted with toluene:methanol mixtures (100:0-85:15, v:v, 120 L total volume). The column fractions were analyzed by TLC. The fractions containing the free base of Vb were combined. Methanesulfonic acid was added to the free base until the pH of the solution was 3.0-3.5 as determined by pH meter by withdrawing an aliquot (0.1 mL), mixing it with water (1.0 mL) and measuring pH (use 2.3 moles of methanesulfonic acid per mole of Vb free base). The crude Vb was separated from the toluene:methanol by filtration and dried under nitrogen on the filter. An HPLC of the crude Vb was taken to determine purity. The Vb was further purified by recrystallizations from acetonitrile:water (7:1, v:v, 65° C.) until the desired purity by HPLC was achieved. Use 25-40 mL of hot recrystallization solvent per gram of crude Vb: as the purity of the Vb increases, the ratio of solvent to Vb increases. While the recrystallization solution was cooling, half of its volume was rotoevaporated off. Vb was vacuum oven dried (20°-25° C.; 0.1 mm Hg) to a constant weight. Yield was 40% of theoretical of white to off-white powder. HPLC: >98% with no impurity greater than 0.5%; ¹ HNMR: (TMS, DMSO-d6) δ 1.57, 2.18, 3.29, 3.44, 3.86, 5.46, 8.07, 8.67, 8.79, 8.95, 9.49.

EXAMPLE 26 (Meso)-2,2'-[1,2-ethanediylbis[imino(1-methyl-2,1-ethanediyl)]]-bis[5-nitro-1H-benz[de]isoquinoline-1,3(2H)-dione]methanesulfonate (1:2) (XXVII)

Part A: (XXI) 1,1-Dimethylethyl-(S)-[2-[(cyanomethyl)amino]-1-methyl-2-oxoethyl]carbamate.

A mixture of aminoacetonitrile hydrochloride (9.25 g, 100 mmol) and N-methylmorpholine (10.1 g, 100 mmol) in 100 ml of THF was stirred for 15 minutes. N-t-BOC-(S)-alanine (18.9 g, 100 ml) and N-methylmorpholine (10.1 g, 100 mmol) in 100 ml of THF was stirred with an ice-salt bath. Isobutyl chloroformate (12.97 ml, 100 mmol) was added at such a rate that the temperature of the mixture won't exceed 10° C. and the mixture of the nitrile-N-methylmorpholine suspension was added after 2 minutes. The mixture was stirred at room temperature overnight. The N-methylmorpholine hydrochloride was removed by filtration and the solvent in the filtrate was evaporated. The remaining liquid was diluted with methylene chloride (500 ml), washed with aq. K₂ CO₃ (2×100 ml), H₂ O (1×100 ml). The layers were separated; and the organic layer dried over anhydrous MgSO₄, filtered and evaporated to give 15.85 g (69.7%) of the crude product. This was purified by column chromatography to give pure XXI (14.88 g, 65.5%), mp 99°-100° C. ¹ H-NMR (CDCl₃) δ 7.32 (broad, 1H, NH), 5.12 (d, 1H, J=5.8 Hz, NH), 4.15 (m, 3H, CH and CH₂), 1.46 (s, 9H, 3 CH₃) and 1.39 (d, 3H, J=7.0 Hz, CH₃). MS (CI) m/e 228 (M+1).

Part B: (XXII) 1,1-dimethylethyl-(S)-[2-[(2-aminoethyl)amino]-1-methyl-2-oxoethyl]carbamate.

A mixture of XXI (2.0 g, 8.8 mmol) and palladium hydroxide (0.5 g) in 15 ml of acetic acid was hydrogenated (50 psi) in a Parr shaker for 11/2 hours. The catalyst in the mixture was removed by filtration. The acetic acid in the filtrate was removed by vacuum distillation to give a light yellow viscous liquid, which was added 15 ml of methanol and 1 g of sodium bicarbonate. The mixture was stirred at room temperature for several hours. The sodium acetate was removed by filtration; and the solvent in the filtrate evaporated to give the crude product. This was purified by column chromatography to give pure XXII (0.92 g, 45.2%) as a viscous liquid. ¹ H-NMR (CDCl₃) δ 7.08 (broad, 1H, NH), 5.28 (broad, 1H, NH), 3.28-3.26 (m, 2H, CH₂), 2.84 (t, 2H, J=5.9 Hz, CH₂), 1.41 (S, 9H, 3 CH₃ ) and 1.34 (d, 3H, J=6.9 Hz, CH₃). MS (CI) m/e 232 (M+1).

Part C: (XXIII) 1,1-Dimethylethyl (meso)-[1,2-ethanediylbis[imino(1-methyl-2-oxo-2,1-ethanediyl)]]bis(carbamate).

A mixture of N-t-BOC-(R)-alanine (0.74 g, 3.9 mmol) and 1,1'-carbonyldiimidazole (0.64 g, 3.9 mmol) in 20 ml of methylene chloride was stirred with an ice bath cooling for 11/2 hours. To this, there was added XXII (0.91 g, 3.9 mmol) in 10 ml of methylene chloride with an ice bath cooling. The mixture was stirred at ambient temperature overnight. The product was collected on a filter to give XXIII (1.22 g, 77.9%) as a white solid. ¹ H-NMR (DMSO-d₆) δ 7.83 (broad, 2H, 2 NH), 6.85 (m, 2H, 2 NH), 3.90 (m, 2H, 2 CH), 3.13 (m, 4H, 2 CH₂), 1.40 (s, 10H, 6 CH₃) and 1.18 (d, 6H, 2 CH₃). MS (CI) m/e 403 (M+1).

Part D: (XXIV) (Meso)-N,N'-1,2-ethanediylbis[2-aminopropanamide]dihydrochloride.

A mixture of XXIII (1.18 g, 2.9 mmol) and 2.7 ml of 4.4N HCl in 40 ml of dioxane was heated to reflux for 5 hours and then cooled to room temperature overnight. The solvent in the mixture was evaporated to give XXIV (0.75 g, 94%) as a white solid. ¹ H-NMR (DMSO-d₆) δ 8.81 (broad, 2H, 2 NH), 8.33 (broad, 4H, 2 NH₂), 3.83 (q, 2H, J=6.9 Hz, 2 CH), 3.21 (broad s, 4H, 2 CH₂) and 1.37 (d, 6H, J=6.9 Hz, 2 CH₃).

Part E: (XXV) (Meso)-N¹,N^(1') -1,2-ethanediylbis[1,2-propanediamine]tetrahydrochloride

To 30 ml or 1M borane THF complex, there was added 0.75 g (2.7 mmol) of XXIV. The mixture was refluxed overnight. After cooling to room temperature, methanol (15 ml) was added slowly to the reaction mixture. The mixture was then refluxed for 3 days. The solvents in the mixture were evaporated. To the residue was added 20 ml of methanol and 1.5 ml of conc. HCl. The mixture was stirred at room temperature for 4 hours, and then the solvent and excess HCl evaporated to give XXV (0.81 g, 93.7%) as a white solid. ¹ H-NMR (D₂ O) δ3.66 (m, 2H, 3.37 (s, 4H), 3.24 (m, 4H) and 1.29 (d, 6H, J=7.0 Hz, 2 CH₃). MS (CDI) m/e 175 (M+1).

Part F: (XXVI) (Meso)-N¹,N^(1') -1,2-ethanediylbis[1,2-propanediamine]

To a freshly prepared solution of sodium ethoxide in ethanol (0.26 g of sodium in 40 ml of ethanol) was added 0.81 g of XXV. The mixture was stirred at room temperature for 1 hour. The sodium chloride was removed by filtration; and the solvent in the filtrate evaporated. The product was isolated from the residue by Kugelrohr distillation (88°-96° C. at 0.4 mm) to give XXVI (0.32 g, 73.4%) as a clear liquid. ¹ H-NMR (CDCl₃) δ 2.88 (m, 2H, 2 CH), 2.63 (m, 4H, 2 CH₂), 2.48 (m, 2H, CH₂), 2.29 (m, 2H, CH₂), 1.54 (broad s, 6H, 2 NH₂ and 2 NH) and 0.96 (d, 6H, J=6.2 Hz, 2 CH₃). MS(CI) m/e 175 (M+1).

Part G: (XXVII) (Meso)-2,2'-[1,2-ethanediylbis[imino(1-methyl-2,1-ethanediyl)]]-bis[5-nitro-1H-benz[de]isoquinoline-1,3(2H)-dione]methanesulfonate (1:2).

A mixture of 3-nitro-1,8-napthalic anhydride (0.78 g, 3.2 mmol) and XXVI (0.28 g, 1.6 mmol) in 25 ml of ethanol was stirred at room temperature overnight and then heated to reflux for 22/3 hours. The solvent in the mixture was evaporated to give the crude products. This was purified by column chromatography to give pure product (0.39 g, 39%) as its free base. This was converted to its methanesulfonate salt, XXVII (0.33 g, 25.3%); mp 243°-244.5° C. (dec). ¹ H-NMR (DMSO-d₆) δ 9.53 (s, 2H, aromatic protons), 8.96 (s, 2H, aromatic protons), 8.82 (d, 2H, J=8.0 Hz, aromatic protons), 8.77, 8.74 (broad, 4H, 2NH₂ ⁺), 8.70 (d, 2H, J=6.9 Hz, aromatic protons), 8.09 (t, 2H, J=7.7 Hz, aromatic protons), 5.47 (m, 2H, 2 CH), 3.87 (m, 2H), 3.43 (m, 2H), 3.27 (broad, 4H), 2.20 (s, 6H, 2 CH₃ SO₃ H) and 1.58 (d, 6H, J=6.6 Hz, 2 CH₃). IR (KBr) 3445 (NH), 1770, 1668 (C═O)cm⁻¹. MS (DCI) m/e 625 (M+1). Anal. Calcd for C₃₂ H₂₈ N₆ O₈ . 2 CH₃ SO₃ H . 1/2 H₂ O (MW 826.53): C, 49.41; H, 4.60; N, 10.17; S, 7.76. Found: C, 49.45, 49.41; H, 4.33, 4.29; N, 10.11, 10.21; S, 7.50, 7.58.

EXAMPLE 27 (S,S)-2,2'-[1,2-ethanediylbis[imino(2-methyl-2,1-ethanediyl)]]-bis[5-nitro-1H-benz[de]isoquinoline-1,3(2H)-dione]methanesulfonate (1:2) (XIXa)

Part A: (XVa) Dimethyl N,N'-1,2-dioxo-1,2-ethanediyl)bis[S-alanine].

A mixture of (S)-alanine methyl ester hydrochloride (14 g, 100 mmol) and oxalyl chloride (4.9 ml, 55 mmol) in 150 ml of benzene was refluxed overnight. After cooling to room temperature, the white solid was collected on a filter to give 12.36 g (95%) of XVa; mp 167°-170° C. ¹ H-NMR (DMSO-d₆) δ 9.15 (d, 2H, 2 NH) 4.40 (quintet, 2H, 2 CH), 3.67 (s, 6H, 2 OCH₃) and 1.40 (d, 6H, 2 CH₃). MS (DCI) m/e 261 (M+1). [α]_(D) -65.32° (c=1.012, AcOH).

Part B: (XVIa) (S,S)-N,N'-bis(2-amino-1-methyl-2-oxoethyl)ethanediamine.

Compound XVa (5.21 g, 20 mmol) was added to a methanol solution saturated with ammonia with an ice bath cooling. The mixture was further bubbled with ammonia for 1 hour; and then stirred at room temperature overnight. The white solid was collected on a filter to give 3.65 g (79%) of XVIa. ¹ H-NMR (DMSO-d₆) δ 8.50 (d, 2H, J=7.7 Hz, 2 NH), 7.50 (s, 2H, NH₂), 7.21 (s, 2H, NH₂), 4.25 (quintet, 2H, J=7.3 Hz, 2 CH) and 1.31 (d, 6H, J=7.3 Hz, 2 CH₃). MS (DCI) m/e 231 (M+1). [α]_(D) +69.14° (c=0.418, DMF).

Part C: (XVIIa) (S,S)-N²,N^(2') -1,2-ethanediylbis[1,2-propanediamine]tetrahydrochloride.

To a mixture of XVIa (3.5 g, 15.2 mmol) in 100 ml of THF, there was added 150 ml of 1M BH₃.THF complex. After refluxing overnight, the reaction mixture was cooled to room temperature and 80 ml of methanol was added slowly. The mixture was refluxed overnight, and a small amount of precipitate present were removed by filtration. The solvents in the filtrate were evaporated; and to the remaining liquid was added 30 ml of methanol and 7.5 ml of conc. HCl with an ice bath cooling. After stirring for 1.5 hours, the mixture was triturated with ethyl ether; and the product was collected on a filter to give 3.92 g (81%) of XVIIa; ¹ H-NMR (D₂ O) δ 3.54 (m, 2H, 2 CH), 3.31 (m, 6H), 3.06 (m, 2H) and 1.28 (d, 6H, J=6.6 Hz, 2 CH₃). MS (DCI) m/e 175 (M+1, free base). [α]_(D) +8.39° (c=0.632, H₂ O).

Part D: (XVIIIa) (S,S)-N²,N^(2') -1,2-ethanediylbis[1,2-propanediamine].

Compound XVIIa (3.2 g, 10 mmol) was added to a freshly prepared sodium ethoxide solution in ethanol (1.03 g of sodium in 50 ml of ethanol). After stirring at room temperature overnight, sodium chloride in the mixture was removed by filtration, and the solvent in the filtrate evaporated. The remaining mixture was purified by Kugelrohr distillation (110°-124° C. at 0.7 mm) to give 1.43 g (82%) of XVIIIa as a clear liquid. ¹ H-NMR (CDCl₃) δ 2.8-2.4 (m, 10H, 4 CH₂ and 2 CH), 1.57 (broad, 6H, 2 NH₂ and 2 NH) and 0.91 (d, 6H, J=5.9 Hz, 2 CH₃) [α]_(D) +120° (c=0.310, benzene).

Part E: (XIXa) (S,S)-2,2'-[1,2-ethanediylbis[imino(2-methyl-2,1-ethanediyl)]]-bis[5-nitro-1H-benz[de]isoquinoline-1,3(2H)-dione]methanesulfonate (1:2).

A mixture of 3-nitro-1,8-naphthalic anhydride (1.46 g, 6.0 mmol) and XVIIIa (0.52 g, 3 mmol) in 30 ml of ethanol was stirred at room temperature overnight. To this, there was added 0.63 g of methanesulfonic acid. After stirring overnight, the product was isolated by filtration and purified by heating in 50 ml of methanol overnight to give 1.37 g (55%) of XIXa; mp 254°-255° C. (dec). ¹ H-NMR (DMSO-d₆) δ 9.55 (d, 2H, J=1.9 Hz, aromatic protons), 9.0 (d, 2H, J=1.9 Hz, aromatic protons), 8.85 (d, 2H, J=8.1 Hz, aromatic protons), 8.73 (d, 2H, J=7.0 Hz, aromatic protons), 8.11 (t, 2H, J=7.9 Hz, aromatic protons), 4.39-4.27 (m, 4H, 2 CH₂), 3.75 (m, 2H, 2 CH), 2.26 (s, 6H, 2 CH₃) and 1.35 (d, 6H, J=5.9 Hz, 2 CH₃). MS (DCI) m/e 625 (M+1). Anal. Calcd for C₃₂ H₂₈ N₆ O₈ . 2 CH₃ SO₃ H H₂ O(MW 834.83): C, 48.92; H, 4.59; N, 10.07; S, 7.68. Found: C, 48.97, 48.84; H, 4.43, 4.46; N, 10.16, 10.13; S, 7.83, 7.84.

EXAMPLE 28 (S,S)-2,2'-[1,2-ethanediylbis[imino(2-methyl-2,1-ethanediyl)]]-bis[¹ H-benz[de]isoquinoline-1,3(2H)-dione]methanesulfonate (1:2) (XXa)

By replacing 3-nitro-1,8-naphthalic anhydride with 1,8-naphthalic anhydride, compound XXa can be prepared.

White solid (78% yield); mp 289°-290° C. (dec). ¹ H-NMR (DMSO-d₆) δ 8.96 (broad, 2H, NH₂ ⁺), 8.80 (broad, 2H, NH₂ ⁺), 8.57-8.53 (m, 8H, aromatic protons), 7.94 (t, 4H, J=7.7 Hz, aromatic protons), 4.45-4.23 (m, 4H, 2 CH₂), 3.81 (m, 2H, 2 CH), 2.28 (s, 6H, 2 CH₃) and 1.36 (d, 6H, J=6.6 Hz, 2 CH₃). MS (DCI) m/e 535 (M+1, free base). Anal. Calcd for C₃₂ H₃₀ N₄ O₄ . 2 CH₃ SO₃ H H₂ O (MW 744.83): C, 54.83; H, 5.41; N, 7.42; S, 8.61. Found: C, 55.18, 55.29; H, 5.17, 5.24; N, 7.42, 7.47; S, 8.66, 8.64.

EXAMPLE 29 (R,R)-2,2'-[1,2-ethanediylbis[imino(2-methyl)-2,1-ethanediyl)]-bis[5-nitro-1H-benz[de]isoquinoline-1,3(2H)-dione]-methanesulfonate (1:2) (XIXb)

Light brown solid (34.5% yield); mp 248°-251° C. (dec). ¹ H-NMR (DMSO-d₆) δ 9.54 (d, 2H, J=2.2 Hz, aromatic protons), 8.99 (d, 2H, J=1.9 Hz, aromatic protons), 8.83 (d, 2H, J=8.0 Hz, aromatic protons), 8.72 (d, 2H, J=6.9 Hz, aromatic protons), 8.10 (t, 2H, J=7.9 Hz, aromatic protons), 4.33-4.18 (m, 4H, 2 CH₂), 3.46 (m, 6H), 2.28 (s, 6H, 2 CH₃) and 1.28 (m, 6H, 2 CH₃). MS(Cl) m/e 625 (M+1). Anal. Calcd for C₃₂ H₂₈ N₆ O₈ . 2 CH₃ SO₃ H (MW 816.81) C, 50.00; H, 4.44; N, 10.09; S. 7.85. Found: C, 50.16; H, 4.34; N, 10.19; S, 7.62.

EXAMPLE 30 (Racemic+Meso)-2,2'-[1,2-ethanediylbis[imino[2-methyl-2,1-ethanediyl]-bis[5-nitro-1H-benz[de]isoquinoline-1,3(2H)-dione]-methanesulfonate (1:2) (XIXc)

Yellow solid (18.9% yield); mp 278°-281° C. (dec). ¹ H-NMR (DMSO-d₆) δ 9.58 (d, 2H, aromatic protons), 9.0 (d, 2H, aromatic protons), 8.85 (d, 2H, aromatic protons), 8.75 (d, 2H, aromatic protons), 8.13 (t, 2H, aromatic protons), 4.50-4.25 (m, 4H, 2 CH₂), 3.80 (m, 2H, 2 CH), 3.40 (m, 4H, 2 CH₂), 2.30 (s, 6H, 2 CH₃) and 1.38 (d, 6H, 2 CH₃). MS (CI) m/e 625 (M+1). Anal. Calcd for C₃₂ H₂₈ N₆ O₈ . 2 CH₃ SO₃ H (MW 816.81) C, 50.00; H, 4.44; N, 10.09; S. 7.85. Found: C, 49.62; H, 4.42; N, 10.07; S, 7.80.

EXAMPLE 31 (R,R)-2,2'-[1,2-ethanediylbis[imino[2-methyl-2,1-ethanediyl]-bis[6-nitro-.sup.1 H-benz[de ]isoquinoline-1,3(2H)-dione]methanesulfonate (1:2) (XXVIIIb)

Yellow solid (17.0% yield); mp 230°-233° C. (dec). ¹ H-NMR (DMSO-d₆) δ 9.03 (broad, 2H, NH₂ ⁺), 8.93 (broad, 2H, NH₂ ⁺), 8.76 (d, 2H, J=8.8 Hz, aromatic protons), 8.68-8.57 (m, 6H, aromatic protons), 8.13 (t, 2H, J=7.7 Hz, aromatic protons), 4.37-4.26 (m, 4H, 2 CH₂), 3.77 (m, 2H, 2 CH), 3.36 (s, 4H, 2 CH₂), 2.25 (s, 5.4H, 1.8 CH₃ SO₃ H) and 1.35 (d, 6H, 2 CH₃). MS (CI) m/e 625 (M+1). Anal. Calcd for C₃₂ H₂₈ N₆ O₈ . 1.8 CH₃ SO₃ H (MW 797.59) C, 50.90; H, 4.45; N, 10.54; S. 7.24. Found: C, 50.65, 50.56; H, 4.36, 4.36; N, 10.22, 10.18; S, 6.96, 6.96.

EXAMPLE 32 (R,R)-2,2'-[1,2-ethanediylbis[imino[2-methyl-2,1-ethanediyl)]-bis[5,8-dinitro-1H-benz[de]isoquinoline-1,3(2H)-dione]methanesulfonate (1:2) (XXIXb)

Light brown solid (21.1% yield); mp 227°-230° C. (dec). ¹ H-NMR (DMSO-d₆) δ 9.84 (d, 4H, J=1.5 Hz, 4 aromatic protons), 9.13 (d, 4H, J=1.4 Hz, aromatic protons), 9.02 (broad, 2H, NH2⁺), 8.86 (broad, 2H, NH2⁺), 4.50-4.25 (m, 4H, 2 CH₂), 3.81 (m, 2H, 2 CH), 3.34 (broad, 4H, 2 CH₂), 2.24 (s, 6H, 2 CH₃ ) and 1.39 (d, 6H, J=4.7 Hz, 2 CH₃). Anal. Calcd for C₃₂ H₂₈ N₆ O₁₂ . 2 CH₃ SO₃ H (MW 906.80) C, 45.03; H, 3.75; N, 12.36; S, 7.06. Found: C, 44.75; H, 3.69; N, 12.21; S, 6.87.

EXAMPLE 42 (Racemic)-2,2'-[1,2-ethanediylbis[imino[2-methyl-2,1ethanediyl]-bis[5-nitro-1H-benz[de]isoquinoline-1,3(2H)-dione]methanesulfonate (1:2) (XXXIV)

The compound was prepared by mixing equal amounts of the corresponding (S,S) and (R,R) enantiomers (i.e., XIXa and XIXb, respectively). Light brown solid (90% yield); mp 254°-255° C. (dec). NMR spectrum is identical with those of XIXa and XIXb. Anal. Calcd for C₃₂ H₂₈ N₆ O₈.2CH₃ SO₃ H (MW 816.81) C, 50.00; H, 4.44; N, 10.29; S, 7.85. Found: C, 49.69; H, 4.21; N, 10.19; S, 7.66.

EXAMPLE 43 (S,S,S)-5-nitro-2-[2-[[2-[[2-(5-nitro-1,3-dioxo-1H-benz[de]isoquinoline-2(3H)-yl)-1-methylethyl]amino]-1-methylethyl]amino]-1-methylethyl]-1H-benz[de]isoquinoline-1,3(2H)-dione]methanesulfonate (1:2) (XXXX)

Part A: (XXXV) Methyl N-[N-[N-[(1,1-dimethylethoxy)carbonyl]-L-alanyl]-L-alanyl]-L-alanine.

To a THF solution (50ml) of (t-BOC)-Ala-Ala-OH (5.0 g, 19.2 mmol) and N-methylmorpholine (3.88 g, 38.4 mmol), there was added isobutylchloroformate (2.62 g, 19.2 mmol) dropwise to maintain the temperature between 10° to 15° C. After addition was completed, the reaction mixture was stirred for another 15 minutes. To this, there was added 2.68 g (19.2 mmol) of (s)-alanine methyl ester hydrochloride. After stirring at ambient temperature overnight, the white N-methylmorpholine hydrochloride was removed by filtration; and the solvent in the filtrate evaporated. The remaining liquid was diluted with methylene chloride (350 ml), washed with 5% sodium bicarbonate (2×150 ml), water (1×150 ml), 0.1N HCl (1×150 ml), water 1×150 ml), brine (1×100 ml), dried over anhydrous magnesium sulfate, filtered and evaporated to give 4.32 g of a white solid, XXXV (65.1% yield): mp 168°-172° C. ¹ H-NMR (CDCl₃) δ 6.70 (m, 2H, 2 NH), 4.98 (broad, 1H), 4.48 (m, 2H, 2 CH), 3.70 (s, 3H, CH₃), 1.38 (s, 18H, 6 CH₃) and 1.30 (m, 6H, 2 CH₃). MS (Cl) m/e 346 (M+1). IR (KBr) 3391, 3319, 3275 (NH), 1742, 1710, 1674, 1638 (C=O) cm⁻¹.[α]²⁵ _(D) -50.33° (C=0.600, CH₂ Cl₂).

Part B: (XXXVI) N-[(1,1-dimethylethoxy) carbonyl]-L-alanyl-L-alanyl-L-alaninamide.

To 80 ml of methanol saturated with ammonia, there was added 2.75 g (7.96 mmol) of XXXV. The reaction mixture was cooled with an ice bath, and then further reacted with ammonia for 10 minutes. The reaction was stirred at ambient temperature overnight. The solvent in the solution was evaporated to give a yellow solid, XXXVI (2.45 g, 93% yield); mp 202°-208° C. ¹ H-NMR (DMSO-d₆) δ 7.83-7.95 (m, 2H, 2 NH), 7.25 (broad, 1H, NH), 7.01 (broad, 2H, NH₂), 4.2 (m, 2H, 2 CH), 3.83 (m, 1H, CH) 1.38 (s, 9H, 3 CH₃) and 1.20 (m, 9H, 3 CH₃). MS (DCl) m/e 331 (M+1). [α]²⁵ _(D) -6.00° (c=0.0600, DMSO).

Part C. (XXXVII) L-alanyl-L-alanyl-L-alaninamide hydrochloride.

A mixture of XXXVI (1.95 g, 5.9 mmol) and 4.4M HCl (2.68 ml) in dioxane was added to 40 ml of dioxane at 0° C. for 2 hr, and then warmed to room temperature overnight. The solvent in the mixture was evaporated to dryness to give 1.77 g of XXXVII as an off-white solid; mp 237°-240° C. (dec). ¹ H-NMR (D₂ O) δ 4.2-4.05 (m, 2H 2 CH), 2.95-3.85 (m, 1H, CH) and 1.25 (m, 9H, 3 CH₃). MS (Cl) m/e 231 (M+1). IR (KBr) 3438, 3294 (NH₂), 1676, 1639 (C═O) cm⁻¹. [α]²⁵ _(D) -19.96° (c=0.606, CH₃ OH).

Part D: (XXXVIII) (S,S,S)-N¹ -(2-amino-1-methylethyl)-N² -(2-aminopropyl)-1,2-propanediamine tetrahydrochloride.

To a mixture of XXXVII (1.70 g, 6.37 mmol) in 150 ml of THF, there was added 58 ml of 1M BH₃.THF complex. The mixture was refluxed overnight to become a clear solution. The solution was cooled in an ice bath and quenched dropwise with 50 ml of methanol. The solution was refluxed overnight. The solvents in the reaction solution were removed by rotary evaporation. To the remaining liquid was added methanol (50 ml) and it was evaporated again to remove trimethylborate. The liquid was diluted with methanol (25 ml) followed by the addition of 4.0 ml of conc HCl. After stirring for 2 hr, this was triturated with ethyl ether, filtered to give 1.10 g (51.7% yield) of XXXVIII as a white solid; mp 277°-278° C. (dec). MS (DCl) m/e 189 (M+1). IR (KBr) 3436 (NH, NH₂) cm⁻¹.

Part E: (XXXIX) (S,S,S)-N¹ -(2-amino-1-methylethyl)-N² -(2-aminopropyl)-1,2 -propanediamine.

To a freshly prepared sodium ethoxide solution (0.32 g of sodium of 20 ml of ethanol), there was added 1.05 g (3.1 mmol) of XXXVIII. The mixture was stirred at room temperature overnight. The sodium chloride was removed by filtration; and the solvent in the filtrate evaporated. The remaining liquid was purified by Kugelrohr distillation (0.4 mm, 94°-104° C.) to give 0.41 g of XXXIX as a light yellow liquid (70.2% yield) ¹ H NMR (CDCl₃) δ 2.90 (m, 1H, CH), 2.80 (m, 2H, 2 CH), 2.53-2.30 (m, 6H, 3 CH₂), 1.58 (broad, 6H, 2 NH₂ and 2 NH) and 0.98 (m, 9H, 3 CH₃).

Part F: (XXXX) (S,S,S)-5-nitro-2-[2-[[2-[[2-(5-nitro-1,3-dioxo-1H-benz[de]isoquinoline-2(3H)-yl)-1-methylethyl]amino]-1-methylethyl]amino]1-methylethyl]-1H-benz[de]isoquinoline-1,3(2H)-dione]methanesulfonate (1:2).

A mixture of 3-nitro-1,8-naphthalic anhydride (1.06 g, 4.4 mmol) and XXXIX (0.41 g, 2.2 mmol) in 25 ml of ethanol was stirred at room temperature overnight and then heated to reflux for 11/4 hours. The solvent in the mixture was evaporated, and the remaining dark residue was purified by column chromatography to give 0.83 g of the free base as a light brown solid (59.1% yield), which was then converted to its methanesulfonate, XXXX (0.65 g; 35.6% yield); mp 189°-192° C. (shrink). ¹ H NMR (CDCl₃) δ 9.28 (d, 1H, J=1.9 Hz, aromatic proton), 9.25 (d, 1H, J=2.2 Hz, aromatic proton), 9.15 (d, 1H, J=2.2 Hz, aromatic proton), 9.12 (d, 1H, J=2.2 Hz, aromatic proton, 8.81 (d, 1H, J=7.3 Hz, aromatic proton, 8.76 (d, 1H, J=7.3 Hz, aromatic proton), 8.46 (d, 1H, J=8.1 Hz, aromatic proton), 8.42 (d, 1H, J=8.4 Hz, aromatic proton), 7.98 (t, 1H, J=7.7 Hz, aromatic proton), 7 094 (t, 1H, J=7.92 Hz, aromatic proton), 5.76 (m, 1H, CH), 4.59 (m, 1H), 4.36 (m, 2H), 404 (m, 1H), 3.91 (m, 1H), 3.96 (m, 1H), 3.39 (m, 2H), 1.99 (s, 6H, 2 CH₃), 1.64 (d, 3H, J=7.0 Hz, CH₃), 1.54 (d, 3H, J=6.6 Hz, CH₃) and 1.48 (d, 3H, J=6.6 Hz, CH₃). MS (DCl) m/e 639 (M+1). Anal. Calcd for C₃₃ H₃₀ N₆ O₈.2CH₃ SO₃ H (MW 830.44) C, 50.60; H, 4.61; N, 10.12; S, 7.72. Found: C, 50.70; H, 4.61; N, 9.98; S, 7.69.

                  TABLE 1a                                                         ______________________________________                                          ##STR14##                                                                     Ex.     X, X'     Y, Y'    R.sup.1, R.sup.7                                    ______________________________________                                                          (stereochemistry)                                             1       3-NO.sub.2                                                                               H        CH.sub.3 (S)                                        2       3-NO.sub.2                                                                               H        CH.sub.3 (racemic + meso)                           3       3-NO.sub.2                                                                               H        CH.sub.3 (R)                                        5       3-NO.sub.2                                                                               6-NO.sub.2                                                                              CH.sub.3 (S)                                        6       4-NO.sub.2                                                                               H        CH.sub.3 (S)                                        7       3-NO.sub.2                                                                               6-NO.sub.2                                                                              CH.sub.3 (R)                                        8       4-NO.sub.2                                                                               H        CH.sub.3 (R)                                        26      3-NO.sub.2                                                                               H        CH.sub.3 (meso)                                     ______________________________________                                    

In Table 1a the position of X and Y is indicated using the numbering for the position in the corresponding naphthalic anhydride, and not the numbering for the 1H-benz[de]isoquinoline-1,3(2H)-dione.

                  TABLE 2                                                          ______________________________________                                          ##STR15##                                                                     Ex.  X, X'   Y, Y'   R.sup.2, R.sup.6                                                                           R.sup.4                                                                               R.sup.7                                ______________________________________                                                    (stereochemistry)                                                   27   3-NO.sub.2                                                                             H       CH.sub.3 (S)                                                                               H      H                                      28   H       H       CH.sub.3 (S)                                                                               H      H                                      29   3-NO.sub.2                                                                             H       CH.sub.3 (R)                                                                               H      H                                      30   3-NO.sub.2                                                                             H       CH.sub.3 (racemic +                                                                        H      H                                                           meso)                                                     31   4-NO.sub.2                                                                             H       CH.sub.3 (R)                                                                               H      H                                      32   3-NO.sub.2                                                                             6-NO.sub.2                                                                             CH.sub.3 (R)                                                                               H      H                                      42   3-NO.sub.2                                                                             H       CH.sub.3 (racemic)                                                                         H      H                                      43   3-NO.sub.2                                                                             H       R.sup.2 CH.sub.3 (S);                                                                      CH.sub.3 (S)                                                                          CH.sub.3 (S)                                                R.sup.6 H                                                 ______________________________________                                    

In Table 2 the position of X and Y is indicated using the numbering for the position in the corresponding naphthalic anhydride, and not the numbering for the 1H-benz[de]isoquinoline-1,3(2H)-dione.

Utility In vitro Growth Inhibitory Activity

L1210 cells were maintained in RPMI-1640 a medium supplemented with 10% heat inactivated fetal bovine serum and 50 mL mercaptoethanol/liter medium (RPMI-L). B16 cells were maintained in RPMI-1640 medium supplemented with 15% heat inactivated fetal bovine serum and antiobiotics (RPMI-C).

Exponentially growing murine leukemia L1210 cells (1×10³ cells) in 0.1 mL medium were seeded on day 0 in a 96-well microtiter plate. On day 1, 0.1 μL aliquot of medium containing graded concentrations of test analogs was added to the initial volume. After incubation at 37° C. in a humidified incubator for 3 days, the plates were centrifuged briefly and 100 mL of the growth medium was removed. Cell cultures were incubated with 50 μL of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT; 1 mg/ml in Dulbecco's phosphate buffer saline) for 4 hours at 37° C. The resulting purple formazan precipitate was solubilized with 200 μL of 0.04N HCl in isopropyl alcohol. Absorbance was read in a Titertek Multiskan MCC scaning well spectrophotometer (Flow Laboratories) at a test wavelength of 570 nm and a reference wavelength of 630 nm.

The ID₅₀ values were determined by a computer program that fit all of the data (8 determinations per concentration and 12 concentrations per test analog) to the following equation:

    Y=((Am-Ao)/(1+(X/ID.sub.50)n))+Ao

where: Am=absorbance of the control cells; Ao=absorbance of the cells in the presence of highest drug concentration; Y=observed absorbance; X=drug concentration; ID₅₀ =dose of drug that inhibits the growth of cells to one half that of the control cells.

Results of the in vitro L1210 growth inhibition testing are shown in Table 3.

                  TABLE 3                                                          ______________________________________                                         Ex. No.      ID.sub.50 (μg/ml)                                              ______________________________________                                          1           0.047                                                              2           0.062                                                              3           0.051                                                             26           0.074                                                             27            0.0025                                                           28           0.21                                                              29           <0.01                                                             30           <0.01                                                             31           0.19                                                              32           0.057                                                             42           <0.001                                                            43           0.04                                                              ______________________________________                                    

In Vivo Tumor Models

Representative compounds of the present invention have been extensively tested in a variety of pre-clinical tests of anti-cancer activity which are indicative of clinical utility. For example, the presently claimed compounds show striking in vivo efficacy against three types of human tumors xenografted in nude mice, namely DLD-2 human colon carcimoma, MX-1 human mammary carcinoma, and LX-1 human lung carcinoma.

In addition, a representative compound of the present invention is active against several murine tumors, including murine M16c mammary adenocarcinoma and murine C51 colon adenocarcinoma. In addition, a representative compound of the invention is active against murine mammary tumors in transgenic mice containing the v-Ha-ras oncogene.

The methods used in the testing of compounds in the in vivo human tumor xenograft models are described below.

In Vivo Human Tumor Xenograft Models

The DLD-2 human colon tumor, MX-1 human mammary carcinoma, and LX-1 human lung tumor were originally obtained from a surgically removed primary colon carcinoma, breast tumor, and non-small lung carcinoma, respectively. The human tumor lines were maintained by serial passage in athymic nude mice. The MX-1 human mammary carcinoma and LX-1 human lung tumor are established tumors used by the NCI. The DLD-2, MX-1, and LX-1 tumor models have been well characterized.

The mice used in these experiments were outbred Swiss mice or BALB/c mice bearing the nude (nu/nu) gene. On day 0 male and female mice weighing 22-30 g are inoculated with 0.2 mL of a 25% tumor mince. This mince is prepared by mincing fresh tumor tissue, grown subcutaneously in passage mice, in sterile physiological saline. Palpable tumors weighing approximately 50 mg appear in the mice within 7-10 days after inoculation. The mice are pair matched by tumor weight and sex into groups of ten each and the test compounds and vehicle control are administered intravenously (i.v.) once daily for nine consecutive days. A >20% decrease in body weight on day 5 following compound administration is considered an indication of toxicity. Tumor measurements and body weights are recorded once a week. Fifteen to 18 days after the initial injection the mice are weighed, sacrificed and the tumors excised and weighed.

The efficacy of the test compounds is determined by the extent of tumor growth inhibition in treated versus vehicle-treated control mice. Initial tumor weights (mg) are calculated from the tumor dimensions (mm) measured from caliper measurements, using the formula for a prolate ellipsoid (mg of tumor weight=(length×width²)/2). Net tumor weights are calculated for each of the treated groups and the vehicle-treated control group by subtracting the initial tumor weight from the final tumor weight on day 15. Results are expressed as a percentage decrease relative to the mean tumor weight for the control vehicle-treated group. ##EQU1##

Activity Criteria

The criteria of the National Cancer Institute (NCI) for activity in the in vivo cancer models were used. Tumor growth inhibition of 58-89% in the DLD-2 assay is considered moderate activity and inhibition of ≧90% is condidered good to excellent activity. Actual tumor regressions (IR=incomplete regression; FR=full regression) indicate excellent to outstanding activity. Compounds demonstrating <58% growth inhibition are considered inactive.

The compounds of Examples 1, 2, 3, 26, 27, and 30 exhibited excellent to outstanding activity against DLD-2 human colon tumors. Example 29 exhibited good to excellent activity against DLD-2 human colon tumors.

In addition, the compounds of Examples 2, 3, 27, 29, and 30 exhibited excellent to outstanding activity in the MX-1 human breast tumor model. Example 1 exhibited good to excellent activity against MX-1 human breast tumor.

Examples 2, 3, 27, and 29 exhibited good to excellent activity against LX-1 human lung tumors.

Activity Against Mammary Carcinomas in Transgenic Mice Containing the ras Oncogene

Transgenic mice carrying the v-Ha-ras oncogene linked to the MMTV promoter were constructed originally in the laboratory of Professor Phil Leder at Harvard University (Sinn et al. (1987) Cell 49: 465-475). The female transgenic animals develop mammary tumors, and thus can be used to evaluate agents for activity against these breast tumors. The growth characteristics of these tumors has been characterized extensively (Diamond and Dexter (1991) Proc. Amer. Assoc. Cancer Res. 32:299) and mimic the clinical situation.

Female ras-containing transgenic mice with breast tumors were treated i.v. with saline controls or with the test compound administered daily for 9 days and the group mean tumor growth rate for each test compound was monitored.

The demonstrated effectiveness of the compounds of the present invention in the human colon, breast, and lung tumor xenograft models indicate that the compounds of the present invention may be useful for the treatment of a broad spectrum of solid tumors in man, and, in particular, tumors of the colon, breast, and lung. This conclusion is further supported by published analyses correlating pre-clinical test results with clinical efficacy of anti-cancer agents. For example, see: Goldin and Venditti (1980) Recent Results Cancer Research 76: 176-191; Goldin et al. (1981) Eur. J. Cancer 17: 129-142; Mattern et al. (1988) Cancer and Metastasis Review 7: 263-284; Jackson et al. (1990) Cancer Investigations 8: 39-47. Based on these published analyses, the broad spectrum and exceptional high level of antitumor activity exhibited by the presently claimed compounds provide strong evidence that the compounds claimed in present invention may have important therapeutic utility in the treatment of cancer in man.

Dosage and Formulation

The antitumor compounds (active ingredients) of this invention can be administered to inhibit tumors by any means that produces contact of the active ingredient with the agent's site of action in the body of a mammal. They can be administered by any conventional means available for use in conjunction with pharmaceuticals, either as individual therapeutic active ingredients or in a combination of therapeutic active ingredients. They can be administered alone, but are generally administered with a pharmaceutical carrier selected on the basis of the chosen route of administration and standard pharmaceutical practice.

The dosage administered will be a tumor-inhibiting amount of active ingredient and will, of course, vary depending upon known factors such as the pharmacodynamic characteristics of the particular active ingredient, and its mode and route of administration; age, health, and weight of the recipient; nature and extent of symptoms; kind of concurrent treatment, frequency of treatment, and the effect desired. Usually a daily dosage of active ingredient can be about 5 to 400 milligrams per kilogram of body weight. Ordinarily, 10 to 200, and preferably 10 to 50, milligrams per kilogram per day given in divided doses 2 to 4 times a day or in sustained release form is effective to obtain desired results.

Dosage forms (compositions) suitable for internal administration contain from about 1.0 milligram to about 500 milligrams of active ingredient per unit. In these pharmaceutical compositions, the active ingredient will ordinarily be present in an amount of about 0.5-95% by weight based on the total weight of the composition.

The active ingredient can be administered orally in solid dosage forms, such as capsules, tablets, and powders, or in liquid dosage forms, such as elixirs, syrups, and suspensions. It can also be administered parenterally, in sterile liquid dosage forms.

Gelatin capsules contain the active ingredient and powdered carriers, such as lactose, sucrose, mannitol, starch, cellulose derivatives, magnesium stearate, stearic acid, and the like. Similar diluents can be used to make compressed tablets. Both tablets and capsules can be manufactured as sustained release products to provide for continuous release of medication over a period of hours. Compressed tablets can be sugar coated or film coated to mask any unpleasant taste and protect the tablet from the atmosphere or enteric coated for selective disintegration in the gastrointestinal tract.

Liquid dosage forms for oral administration can contain coloring and flavoring to increase patient acceptance.

In general, water, a suitable oil, saline, aqueous dextrose (glucose), and related sugar solutions and glycols such as propylene glycol or polyethylene glycols are suitable carriers for parenteral solutions. Solutions for parenteral administration contain preferably a water soluble salt of the active ingredient, suitable stabilizing agents, and if necessary, buffer substances. Antioxidizing agents such as sodium bisulfite, sodium sulfite, or ascorbic acid either alone or combined are suitable stabilizing agents. Also used are citric acid and its salts and sodium EDTA. In addtion, parenteral solutions can contain preservatives, such as benzalkonium chloride, methyl- or propyl-paraben, and chlorobutanol.

Suitable pharmaceutical carriers are described in Remington's Pharmaceutical Sciences, Mack Publishing Company, a standard reference text in this field.

Useful pharmaceutical dosage forms for administration of the compounds of this invention can be illustrated as follows.

Capsules: Capsules are prepared by filling standard two-piece hard gelatin capsules each with 100 milligrams of powdered active ingredient, 175 milligrams of lactose, 24 milligrams of talc, and 6 milligrams magnesium stearate.

Soft Gelatin Capsules: A mixture of active ingredient in soybean oil is prepared and injected by means of a positive displacement pump into gelatin to form soft gelatin capsules containing 100 milligrams of the active ingredient. The capsules are washed and dried.

Tablets: Tablets are prepared by conventional procedures so that the dosage unit is 100 milligrams of active ingredient, 0.2 milligrams of colloidal silicon dioxide, 5 milligrams of magnesium stearate, 275 milligrams of microcrystalline cellulose. 11 milligrams of cornstrach and 98.8 milligrams of lactose. Appropriate coatings may be applied to increase palatability or delay absorption.

Injectable: A parenteral composition suitable for administration by injection is prepared by stirring 1.5% by weight of active ingredient in 10% by volume propylene glycol and water. The solution is made isotonic with sodium chloride and sterilized.

Suspension: An aqueous suspension is prepared for oral administration so that each 5 milliliters contain 100 milligrams of finely divided active ingredient, 200 milligrams of sodium carboxymethyl cellulose, 5 milligrams of sodium benzoate, 1.0 grams of sorbitol solution, U.S.P., and 0.025 milliliters of vanillin.

In the present disclosure it should be understood that the specified materials and conditions are important in practicing the invention but that unspecified materials and conditions are not excluded so long as they do not prevent the benefits of the invention from being realized. 

What is claimed is:
 1. A method for preparing a compound of the formula: ##STR16## said method comprising: (a) reacting alanine methyl ester with oxalyl chloride followed by treatment with ammonia in methanol to yield a compound of the formula: ##STR17## (b) reduction of the amide functionality with diborane in tetrahydrofuran followed by neutralization the tetrachloride salt with sodium ethoxide to yield a compound of the formula (XVIII).
 2. A method for preparing a compound of the formula: ##STR18## said method comprising: (a) reacting t-BOC-(S)-alanine with isobutylchloroformate in the presence of N-methylmorpholine, followed by reaction with aminoacetonitrile to yield a compound of the formula: ##STR19## (b) reducing the nitrile of (XXI) with palladium hydroxide in acetic acid to yield a compound of the formula: ##STR20## (c) reacting t-BOC-(R)-alanine with 1,1'-carbonyldiimidazole followed by reaction with amine (XXII) to yield a compound of the formula: ##STR21## (d) removing the t-BOC group with mineral acid followed by reduction of the amide function with diborane followed by neutralization of the tetrahydrochloride salt with sodium ethoxide to yield a compound of the formula (XXVI).
 3. A method for preparing a compound of the formula: ##STR22## said method comprising: (a) reacting (t-BOC)-alaninyl alanine with isobutylchloroformate in the presence of N-methyl morpholine, followed by reaction with (S)-alanine methyl ester to yield a compound of the formula: ##STR23## (b) reacting compound (XXXV) with ammonia in methanol to yield a compound of the formula: ##STR24## (c) reduction of the amide functionality with diborane in tetrahydrofuran followed by neutralization of the tetrahydrochloride salt with sodium ethoxide to yield a compound of the formula (XXXIX).
 4. A process for preparing the free base form of a compound of formula (IV): ##STR25## comprising the steps of: (a) reacting in solution a compound of the formula: ##STR26## wherein R¹⁰ is an amine protecting group that can be removed without the addition of acid,with a suitable carboxyl activating agent, said carboxyl activating agent facilitating the formation of an amide bond, followed by reaction with ethylenediamine to yield a compound of formula (XXXXVII): ##STR27## (b) contacting the compound of formula (XXXXVII) with a suitable reagent or combination of reagents to effect the removal, without the addition of acid, of the R¹⁰ amine protecting groups from the compound of formula (XXXXVII) to yield in solution the free base form of the compound of formula (XXXXVIII): ##STR28## (c) isolating the compound of formula (XXXXVIII) by removal of unwanted solids from the reaction medium and contacting the reaction solution with a suitable solvent to effect precipitation of the free base form of the compound of formula (XXXXVIII); (d) reacting the resultant compound of formula (XXXXVIII) in solution with a suitable amide reducing agent, said amide reducing agent not resulting in the formation of distillable complexes of the amine reducing agent and the compound of formula (IV), to yield the free base form of the compound of formula (IV).
 5. A process of claim 4, wherein R¹⁰ is selected from:2,7-di-t-butyl-[9-(10,10-dioxo-10,10,10,10-tetrahydrothioxanthyl)]methyl carbamate; 2-trimethylsilylethyl carbamate; 2-phenylethyl carbamate; 1,1-dimethyl-2,2-dibromoethyl carbamate; 1-methyl-1-(4-biphenylyl)ethyl carbamate; benzyl carbamate; p-nitrobenzyl carbamate; 2-(p-toluenesulfonyl)ethyl carbamate; m-chloro-p-acyloxybenzyl carbamate; 5-benzyisoxazolylmethyl carbamate; p-(dihydroxyboryl)benzyl carbamate; m-nitrophenyl carbamate; o-nitrobenzyl carbamate; 3,5-dimethoxybenzyl carbamate; 3,4-dimethoxy-6-nitrobenzyl carbamate; N'-p-toluenesulfonylamino-carbonyl; t-amyl carbamate; p-decyloxybenzyl carbamate; diisopropylmethyl carbamate; 2,2-dimethoxycarbonylvinyl carbamate; di(2-pyridyl)methyl carbamate; 2-furanylmethyl carbamate; phthalimide; dithiasuccinimide; 2,5-dimethylpyrrole; benzyl; 5-dibenzylsuberyl; triphenylmethyl; benzylidene; or diphenylmethylene.
 6. A process of claim 4, wherein R¹⁰ is selected from:2-phenylethyl carbamate; benzyl carbamate; p-nitrobenzyl carbamate; 2-(p-toluenesulfonyl)ethyl carbamate; 5-benzyisoxazolylmethyl carbamate; m-nitrophenyl carbamate; o-nitrobenzyl carbamate; 3,5-dimethoxybenzyl carbamate; 3,4-dimethoxy-6-nitrobenzyl carbamate; p-decyloxybenzyl carbamate; di(2-pyridyl)methyl carbamate; 2-furanylmethyl carbamate; phthalimide; benzyl; or diphenylmethylene.
 7. A process of claim 4 wherein in step (c) the suitable solvent to effect precipitation of the compound of formula (XXXXVIII) is t-butylmethyl ether.
 8. A process of claim 4 wherein step (c) comprises contacting the reaction solution or solvent exchanging of the reaction solution with t-butylmethyl ether to precipitate the compound of formula (XXXXVIII) followed by separation of solids and liquid to isolate the compound of formula (XXXXVIII).
 9. A process of claim 4 wherein the amide reducing agent is selected from: lithium aluminum hydride, AlH₃, diisobutyl aluminum hydride, NaAlEt₂ H₂, sodium bis(2-methoxyethoxy)aluminum hydride, or catalytic hydrogenation with Raney nickel of a corresponding thioamide.
 10. A process of claim 4 wherein the amide reducing agent is lithium aluminum hydride.
 11. A process of claim 4 wherein the carboxyl activating agent is selected from: N-ethyloxycarbonyl-2-ethyloxy-1,2-dihydroquinoline; N-isobutyloxycarbonyl-2-isobutyloxycarbonyl-1,2-dihydroquinoine; isobutyl chlorocarbonate; diphenylphosphorazidate; carbonyldiimidazole; ethoxyacetylene; ethoxyacetylene in combination with 1-hydroxybenzotriazole or N-hydroxysuccinimide; dicyclohexylcarbodiimide; or dicyclohexylcarbodiimide in combination with 1-hydroxybenzotriazole or N-hydroxysuccinimide.
 12. A process of claim 4 wherein the carboxyl activating agent is selected from: isobutyl chlorocarbonate or 1,1'-carbonyldiimidazole.
 13. A process of claim 4, wherein R¹⁰ is benzyl carbamate. 